The present invention relates to the art of trucks and, more particularly, to improvements in dump trucks of the type including an integrated spreader system for conveying material through a tailgate opening while facilitating the hauling of long items or the hauling and/or dumping of material without interference from auxiliary structures carried by the truck for use in conjunction with the integrated spreader system.
Co-pending application Ser. No. 677,139 filed Jul. 9, 1996, now U.S. Pat. Nos. 5,890,867 and 5,823,734 issued Oct. 20, 1998 are incorporated herein by reference to provide background information with respect to one type of vehicle to which the improvements according to the present invention are applicable.
Trucks, such as dump trucks, have been used heretofore to convey materials such as salt, dirt, gravel, and the like for the purposes of spreading such materials onto road surfaces to improve the traction of vehicles traveling thereon during hazardous driving conditions. Dump trucks have also been used to carry and dispense asphalt on road surfaces for repair and maintenance purposes. Materials of the foregoing nature are commonly dispensed from the truck by tilting the dump body so that the materials flow therefrom by gravity and/or by conveying the materials within the dump body out through an opening in the rear wall or tailgate thereof. Dump trucks with such integrated conveyor systems are shown, for example, in the foregoing U.S. Pat. No. 5,823,734 and in U.S. Pat. No. 4,886,214 to Musso, et al. and U.S. Pat. No. 5,397,172 to Musso, et al. In this respect, each of these patents discloses a dump truck in which the dump body or material receptacle is provided with an endless conveyor for conveying materials in the dump body to an adjustable feedgate mounted within an opening in the tailgate of the dump body for selective positioning relative to the conveyor to control the dispensing of materials from the dump body. When the truck is not being used to achieve controlled discharge of granular material such as salt, it is desirable that the truck be capable of an alternate use or uses so as to preclude its being idle. Accordingly, the feedgate arrangements in the foregoing patents are mounted on the tailgate of the dump truck and associated therewith such that the tailgate can be opened to provide for the dumping of materials from the dump body by elevating the latter and/or the hauling of elongated objects such as trees, lumber, pipes and the like in a manner which minimizes interference between the materials being hauled and the feedgate apparatus. As will be apparent from the foregoing patents, if the feedgate apparatus is mounted on a tailgate which is pivotal about a horizontal axis at the upper end of the dump body, granular materials and the like in the dump body flowing through the open rear end thereof are likely to have abrasive contact with the feedgate apparatus. Similarly, if the feedgate apparatus is mounted on a tailgate which is pivotal about a horizontal axis at the lower end of the dump body, the feedgate apparatus has to be displaced to a position relative to the tailgate which minimizes contact between long materials being hauled and the feedgate apparatus. Moreover, if the dump truck is to be used for dumping granular materials other than through the use of the feedgate apparatus, it is difficult to position the feedgate apparatus relative to the tailgate so as to preclude abrasive contact of the material being dumped with component parts of the feedgate apparatus. Moreover, the movement of material across the tailgate and the feedgate apparatus results in problems of jamming of the component parts thereof and damage thereto by the abrasive contact of material therewith as well as damage resulting from efforts to move the component parts when they are jammed. All of these problems result in increased maintenance time and cost in connection with clearing jams and/or repairing or replacing damaged component parts.
In accordance with the present invention, feedgate arrangements are provided by which the foregoing and other disadvantages and problems with feedgate assemblies heretofore available are minimized or overcome. More particularly in accordance with the invention, a feedgate is removably mounted on one or the other of the bottom or tailgate of the dump body of a dump truck whereby, during periods of non-use of the feedgate, the latter can be removed and the discharge opening in the tailgate covered so as to provide for use of the dump truck for other purposes without interference from or potential damage to the feedgate components. More particularly in this respect, when the opening in the tailgate is closed such as by a flat plate, the truck can be used for hauling a variety of materials which can be dumped when the tailgate is released for pivotal movement to an open position and, with the feedgate removed, such dumping is achieved without any potential interference from or damaged to the component parts of the feedgate. Moreover, if the tailgate is pivotal relative to the truck bed about the lower edge of the tailgate, the latter can be opened to a flat condition for the hauling of elongated objects such as trees, lumber, pipes, and the like. Again, with the feedgate removed such materials at most engage the cover plate for the opening in the tailgate, thus avoiding potential damage to the component parts of the feedgate. In use, whether mounted on the bottom or tailgate of the dump body of a dump truck, the feedgate is mounted inwardly adjacent the tailgate about the periphery of the discharge opening therethrough and has a wall forwardly of the tailgate having a passageway therethrough receiving a rear portion of the material conveyor in the bottom of the dump receptacle and which passageway is provided with a door for controlling the size thereof and thus the rate of discharge of material through the opening in the tailgate during operation of the conveyor. Mounting and removal of the feedgate assembly from the bottom or tailgate can be achieved through a variety of mounting arrangements which are structurally simple and easy to manipulate so as to minimize the time and effort required to achieve mounting and removal of the feedgate unit. It will be appreciated too that when the feedgate is not in use and is removed from the dump truck and suitably stored it is protected from exposure to adverse weather and other potential damage attendant to having a feedgate arrangement permanently attached to the vehicle.
It is accordingly an outstanding object of the present invention to provide improvements in connection with feedgates associated with conveyor mechanisms in dump trucks for controlling the rate of discharge of materials through an opening in the rear end of the dump receptacle.
A further object is the provision of feedgate arrangements associated with the material receptacle of a dump truck in a manner which optimizes protection against damage to the component parts of the feedgate or interference thereof with materials being hauled by the truck during periods of non-use of the feedgate for controlling the flow rate of material discharge of the truck.
Still another object is the provision of feedgate arrangements for a truck of the foregoing character which optimize use of the truck for hauling and/or dumping a wide variety of materials when the truck is not being used in a manner requiring the feedgate to control the discharge rate of material therefrom.
Yet another object is the provision of feedgate arrangements which are readily mountable on and removable from one of the bottom and tailgate of a dump truck.
Still a further object is the provision of feedgate arrangements of the foregoing character which avoids the maintenance and/or replacement costs heretofore encountered with respect thereto as a result of their being mounted on a dump truck during periods of use of the latter which do not require a feedgate.